An alternative approach to systematically modeling PWM DC/DC converters in DCM based on the graft scheme

This paper presents on alternative approach to systematically modeling PVM DC/DC converters operated in discontinuous conduction mode (DCM) based on the graft scheme. With the graft scheme, the converters whose active switches are with a common node and operating in unison can be integrated to form a single-stage converter (SSC). The small signal models of SSC can be, therefore, derived by combining those of its originally separate converters. Using the proposed approach can help to yield highly related dynamic models of the converters in a family, and in addition, physical insights between the converters can be readily identified. Moreover, the expressions of the small signal models for the SSCs operated in DCM can be extended to those in CCM operation. This has made the proposed modeling method be valuable and viable. Experimental measurements have demonstrated that the small signal model of an SSC derived with the proposed approach is highly accurate.